Electronic, optical, and thermoelectric efficiency of novel Li-based ternary chalcogenides: First-principles study

Abstract

The distinguishing features of Li-based ternary chalcogenides are their high thermal stability and adjustable optical characteristics. The presentcomputational investigations focused on the complex interactions between the optical, thermal, and electronic properties of novel LiSmX2 (X = S, Se) ternary chalcogenides. The calculated formation energy and cohesive energy values confirm the stability of these materials. The phonon dispersion results confirm their thermodynamic stability. The predicted spin-polarized band structure calculation signifies an indirect energy gap in both materials. The negative trend in the ε1(ω), indicates that the response of these materials is more analogous to a metal within the given energy range. The intense peaks in the reflectivity spectra suggest that these materials can be employed as filter against UV radiations. Electronic band structures of LiSmS2 and LiSmSe2 may further improve the noticed linear rise in the thermal conductivity that helps electrons transmit heat more efficiently. Our present study may open the door to deeper investigations into these semiconductors’ optoelectronic and thermoelectric characteristics andpotential use in optoelectronic and thermoelectric devices.